To heat and melt solid aluminum to be regenerated without oxidizing.

While pouring molten aluminum onto the solid aluminums to be treated, the solid aluminum and the molten aluminum are together charged into molten aluminum to continuously melt the solid aluminum. A mixing tube 6 having an aluminum feeding-in part for receiving the solid aluminum at the upper part is vertically arranged at one side of a melting furnace and the lower end of the mixing tube 6 is inserted into below the molten metal surface level in the melting furnace. The one end of a feeding-out tube 12 for the molten aluminum is faced to the upper part of the aluminum feeding-in part and the other end of the feeding-out tube 12 is connected to a spouting tube 13 of a molten metal pump.